PERL-994 Stop GridFSBucket::DownloadStream length of undef warnings
PERL-994 Stop GridFSBucket::DownloadStream length of undef warnings

xdg/mongo-perl-driver,xdg/mongo-perl-driver,dagolden/mongo-perl-driver,mongodb/mongo-perl-driver,mongodb/mongo-perl-driver,mongodb/mongo-perl-driver,dagolden/mongo-perl-driver,dagolden/mongo-perl-driver,dagolden/mongo-perl-driver,xdg/mongo-perl-driver